ANNA KARLOVNA, än'nȧ kär'lŏv-nȧ, or frequently, Anna Leopoldovna (1718-46). Regent of Russia during the minority of her son Ivan. She was the daughter of Charles Leopold, Duke of Mecklenburg, and of Catharine, sister of the Russian Empress, Anna Ivanovna (q.v.). In 1730 she married Anthony Ulric, Duke of Brunswick-Wolfenbüttel. Her son, Ivan, born August 24, 1740, was appointed by the Empress Anna Ivanovna as her successor. The Empress died in October, 1740, and Biron, whom she had made regent, was overthrown within a month. Anna Karlovna now proclaimed herself Grand Duchess and Regent of Russia; but she showed no capacity for managing the affairs of a great country, spent her time in indolent enjoyments, and resigned herself very much to the guidance of one of the ladies of her court, Julia von Mengden. A conspiracy was formed by a party desirous of raising to the throne Elizabeth, daughter of Peter the Great and Catharine, and this was accomplished on December 6, 1741. The infant Ivan was sent to the castle of Schlüsselburg, where he was afterward murdered; Anna and her husband were condemned to prison for life and conveyed to Kholmogory, on the White Sea, where she died in childbed. Her husband remained a prisoner for thirty-nine years, and died in 1780.